R&D / Technology – Segment-Handling Robot for Next-Generation Thirty Meter Telescope (TMT)
Ensures accurate, flexible, and safe replacement of segment mirrors
The primary mirror of TMT® consists of 492 segment mirrors. The Segment-Handling Robot is the key technology in the world’s first*1 Segment Handling System (SHS), which is designed to replace the mirrors safely and efficiently, and to contribute to revealing the first galaxies and stars in the history of the universe by reducing the time needed to replace the mirrors and increasing observation time. These contributions are expected to open a new horizon in astronomy.
Vision sensor technology for accurate measurement of the segment mirrors
The difficulty of measuring mirrors with high reflectivity is resolved by projecting a checkered flag pattern on the mirrors.
Three developed vision sensors enable the robot to safely approach the mirrors based on accurate recognition of position and attitude.
Force control technology for flexible handling of the segment mirrors
Our force control technology uses a force sensor to detect loads within an accuracy of less than 1kg during the robot’s motions in six degrees of freedom. It also enables gentle yet flexible handling by the robot, so that the mirrors are held securely even at times of power outage caused by massive earthquakes.
Flexible handling makes it possible to compensate for any deformation caused by the heavy weight of the mirrors, which weigh about 250kg, and to remove or install the mirrors on the installation shaft with only a 0.5mm clearance.
Mechanism and drive technology for safe transportation of the segment mirrors
An originally designed parallel link mechanism consisting of six links simultaneously enables both long stroke motion along the Z axis, and motions by the robot in six degrees of freedom.
The long stroke motion provides enough space between the primary mirror and the robot to transport the grasped mirror safely.
- According to an internal survey, as of Feb. 17, 2016